The invention relates to determine asphalt content of a hot mix sample.
A test method has been developed by the National Center of Asphalt Technology (NCAT) to determine the asphalt content of hot mix asphalt by ignition. (1990 sponsored by FHWA). This test method is an alternative replaced The Chlorinated solvents test which is not environmentally safe to use it is an ozone depleting compounds and the US environmental protection agency's in 1990 clean air Act Amendments discontinuation of trichloroethane production after Dec. 31, 1995. in addition to environmental risks these solvent are expensive and difficult to dispose.
Other method Nuclear Asphalt Content (NAC) gives rapid results of Asphalt Content by using the nuclear gauge but do not allow the determination of aggregate gradation of the hot mix.
Other method Biodegradable solvent can be used but they are time consuming, and disposal of the solvent are not safe environmentally.
Finally 1994 the (NCAT) ignition method which use a furnace to ignite the asphalt cement. 1200 grams of hot mix is subjected to an elevated temperature of 538 C in a furnace to ignite and burn the asphalt cement the process take 30 to 40 minutes and the aggregate gradation can then be determined using standard sieve analysis.